Electrical connection



H; A. SHEWARD ELECTRICAL CONNECTION July .9, 1935.

Filed Jan. l2, 1953 2 Sheets-Sheet l @/ZZQ//ZZ July 9, 1935. H A, SHEWARD 2,007,617

ELECTRICAL CONNECTION Filed Jan. l2, 1933 2 Sheets-Sheet 2 Patented July 9, 1935 fUNITED STATES PATNT oFFIcE 1 claim.

This kinvention pertains to electrical connections, and more particularly to a cord connection for all types of electrical appliances, such as sadirons, cooking applianceselectric clippers, vibrators, and the like.

The invention has primarily for its object to provide a comparatively simple, durable, and elficient electrical cordV connection of either the socket or plug type, and comprising means for permitting free universal movement of the cord with constant positive electric connection in all positions. Y

Incidental to the foregoing, a more specic object resides in the provision of an electrical connection embodying a universal joint of the ball and socket type, in connection With novel means for maintaining the electrical contactV between relatively movable parts.

With the above and other objects in View, which will appear as the description proceeds, the invention resides in the novel construction, combination and arrangement of parts, substantially as hereinafter described and more particularly dened by the appended claims, it being understood l that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.

In the accompanying drawings is illustrated one complete example of the physical embodiment of the present invention constructed according to theY best mode so far devised for the practical application of the principles thereof.

' In the drawings:-

Figure l is a longitudinal section through a connection constructed in accordance with the present invention, the same being taken on the line I-I of Figures 2 and 4.

Figure 2 is a similar section taken on the line 2-2 of Figures 4 and 5.

Figure 3 is an elevation with parts broken away and in section.

Figure 4 is a transverse section taken on the line 4 4 of Figure 2, and

Figure 5 is a transverse section taken on the line 5--5 of Figure 2.

Referring now more particularly to the accompanying drawings, the numeral I designates a body member formed from any suitable insulating material, and preferably composition material, such as Bakelite, which may be cast in suitable dies. The body member I comprises a boss 2 having formed thereon adjacent one end a semi--spherical head 3. Formed on the lopposite end of the boss is one section of a split casing 4, which serves to house the wiring connections for the cord, as will be hereinafter explained. Cooperating with the casing section 4, and complementary thereto, is a cover section 5, provided with a out-out portion 6 in its rear end, which straddles the boss 2, as best shown in Figurev 1.

Surrounding the body member I is a metallic shell l, which is split longitudinally to form upper and lower sections 8 and 9, respectively, while the upper section 8 is split transversely intermediate its ends and adjacent the cover section 5 of the contact housing, thus forming a removable plate il?, which renders access to the contact housing when desired. As best shown in Figure 1, the two sections Il and 5 of the contact housing,

as well as the sections 9 and I0 of the outer shell,

are locked together in assembled position by means of a bolt I I having a barrel nut I 2 threaded on its lower end. The forward end of the outer shell is out out for reception of a cushioning ferrule I3, through which the cord passes, as indicated in dotted lines in Figure 1. Obviously, the ferrule prevents contact between the cor-d and `outer shell, and being preferably formed from resilient material, such as rubber, prevents wear and mutilationV of the cord.

The rear ends of the outer shell sections terminate in semi-spherical portions I4, which are shaped to the semi-spherical head 3, and project beyond the same to form a complete closure for the universal connection, regardless of the relative position of the parts, as will be hereinafter explained more in detail.

Projecting longitudinally through the boss 2 of the body member is a stud I5, having a ball I6 threaded on one end concentrically with the spherical head 3, While the opposite end has secured thereon a Contact strip Il, preferably cast into the boss 2, and secured to the end of the rod I5 by a nut Il', which is subsequently covered with suitable insulating material I8, as best shown in Figure 2. The exposed portion of the contact member Il is provided with a threaded recess for reception of a screw I9 for attachment of the wire. In addition to the contact I'I a second contact strip is provided, which is preferably cast into the boss 2 and embedded in the inner face of the spherical head 3. The boss 2 is provided with a cut-out recess 2l adjacent its outer end, which exposes the end of the contact strip 20 for attachment of one of the wires of the electric cord by means of the screw 22.

Here it will be noted that the opposite sides of the lower casing section 4 are provided with angular notches 23 alined with the contact screws I9 and 22, in order to permit the use of ing material 34.

a screw driver, or other tool, in attaching the wires of the cord to the contacts. The upper casing section 5 is provided on its edges with nibs 23, corresponding to the notches 23 and forming a closure therefor when the casing is assembled. Also, in order to relieve strain upon the wiring connections, the boss 2 has formed thereon the lateral projections 24, around which the cords are turned prior to attaching the wires to the contacts, as best illustrated in Figure 1.

While the present invention may be embodied in connections of various types, the present form illustrated comprises a wall plug including a head 25, which carries the usual prongs 26 and 21, preferably cast into the head, as shown in Figure 2, wherein it will be seen that the prong 26 projects through the head and is embedded in the boss 28, which is provided with a shoulder 29 adjacent its inner end, for reception of a semispherical contact shell 30, secured on the boss by upsetting the end of the prong 26. Also, in order to provide secure, rigid connection between the contact shell 30 and the boss 23, an anchor strip 3I may be cast into the boss, as shown in Figure 3, its outer end being upset over the shell 30.

As best shown in Figure 2, the prong 21, which is embedded in the head 25, is secured on the stud 32 by means of a nut 33, the same being subsequently covered by suitable plastic insulat- Threaded on the opposite end of the stud 32 and abutting the end of the boss 28, is a ferrule 35, which is exteriorly threaded for reception of the retaining nut 36, that engages the ball I6 to provide a universal connection between the body member I and the stationary plug section, which carries the prongs 26 and 21. To frictionally hold the relatively movable sections in adjusted position, and at the same time compensate for any wear that may occur in the ball and socket connection, a washer 31 is positioned within the ferrule 35 and is provided with a spherical seat for reception of the ball I6. A spring 38, disposed between the ferrule and washer 31, serves to frictionally hold the washer 31 into engagement with the ball I6.

In order to provide constant electrical contact between the relatively movable parts, a sector 39 is secured to the inner face of the semi-spherical head 3 and is connected to the contact strip 20 by a rivet 40, or any other suitable form of connection. Projecting from the sector 39 at suitably spaced intervals are the resilient contact ngers 4I, which engage Vthe spherical contact shell 30, thus forming an electrical connection between the prong 26 and the contact strip 20. The electrical connection for the contact I1 is obtained through the rod I5, the ball and socket connection and the stud 32. Thus it will be seen that regardless of the relative position of the movable parts, contact is maintained at all times, and inasmuch as a plurality of contact lingers are provided, which resiliently engage the contact shell 30 at spaced intervals, possibility of arcing, with consequent deterioration of the contact nngers, is reduced to a minimum. f

In order to provide a complete closure for the universal connection, and prevent exposure of the contacts, a transversely split shell 42 is mounted on the head 25, it being noted that a slight clearance is provided between the section 43 and the spherical end of the shell 1, which permits the spring 38 to take up any wear that might occur in the ball and socket connection. The outer section 44 snugly engages the shell 1, and is provided with spaced radial ears 45 secured to the finger projections 46, formed on section 43, by means of bolts 41.

From the foregoing explanation, taken in connection with the accompanying drawings, it will be readily seen that a comparatively simple and durable universal connection has been provided for electrical cords utilized upon various types of appliances, which permits free universal movement of the cord and eliminates frequent breakage often accompanied by serious damage through arcing, as well as injury to the user. It will also be seen that the connection is exceedingly neat and attractive in appearance, and, because of its compactness, the same can be readily employed wherever plug connections are used.

I claim:

An electrical connection comprising an insulated body member embodying a boss and a semi-spherical head carried thereby, a split casing surrounding said boss and head, electric terminals carried by said boss, a movable plug provided with electrical contacts, a semi-spherical contact shell carried by said plug, resilient fingers engaging said shell and connected with one of the terminals carried by said boss, a ball and socket coupling between said body member and plug, said coupling having electrical Contact with the other of said terminals carried by the boss, and a split spherical shell carried by said plug and body member to form a complete housing therefor, the sections of said shell having relative universal movement.

HOWARD A. SHEWARD. 

